Extracorporeal apheresis therapy for Alzheimer disease-targeting lipids, stress, and inflammation

Neuroinflammation of Microglial Regulation in Alzheimer's Disease: Therapeutic Approaches

Alzheimer's disease (AD) is a complex degenerative disease of the central nervous system that is clinically characterized by a progressive decline in memory and cognitive function. The pathogenesis of AD is intricate and not yet fully understood. Neuroinflammation, particularly microglial activation-mediated neuroinflammation, is believed to play a crucial role in increasing the risk, triggering the onset, and hastening the progression of AD. Modulating microglial activation and regulating microglial energy metabolic disorder are seen as promising strategies to intervene in AD. The application of anti-inflammatory drugs and the targeting of microglia for the prevention and treatment of AD has emerged as a new area of research interest. This article provides a comprehensive review of the role of neuroinflammation of microglial regulation in the development of AD, exploring the connection between microglial energy metabolic disorder, neuroinflammation, and AD development. Additionally, the advancements in anti-inflammatory and microglia-regulating therapies for AD are discussed.

Navigating the metabolic maze: anomalies in fatty acid and cholesterol processes in Alzheimer's astrocytes

Alzheimer's disease (AD) is the most common cause of dementia, and its underlying mechanisms have been a subject of great interest. The mainstream theory of AD pathology suggests that the disease is primarily associated with tau protein and amyloid-beta (Aβ). However, an increasing body of research has revealed that abnormalities in lipid metabolism may be an important event throughout the pathophysiology of AD. Astrocytes, as important members of the lipid metabolism network in the brain, play a significant role in this event. The study of abnormal lipid metabolism in astrocytes provides a new perspective for understanding the pathogenesis of AD. This review focuses on the abnormal metabolism of fatty acids (FAs) and cholesterol in astrocytes in AD, and discusses it from three perspectives: lipid uptake, intracellular breakdown or synthesis metabolism, and efflux transport. We found that, despite the accumulation of their own fatty acids, astrocytes cannot efficiently uptake fatty acids from neurons, leading to fatty acid accumulation within neurons and resulting in lipotoxicity. In terms of cholesterol metabolism, astrocytes exhibit a decrease in endogenous synthesis due to the accumulation of exogenous cholesterol. Through a thorough investigation of these metabolic abnormalities, we can provide new insights for future therapeutic strategies by literature review to navigate this complex metabolic maze and bring hope to patients with Alzheimer's disease.

Early Benefits with Potential Long-Term Risks of a Comprehensive Intervention on Serum Cortisol Levels and Cognitive Performance in Patients with Alzheimer's Disease

Background

Elevated cortisol levels represent a risk factor for Alzheimer's disease (AD), prompting treatments to lower hormone concentrations for preventive or therapeutic purposes.

Objective

To assess the efficacy of a comprehensive intervention (CI) in modulating serum cortisol levels in patients with AD.

Methods

CI consisted in a 2-month protocol involving cognitive stimulation, psychological support, lifestyle guidance, leisure activities, and socialization. AD subjects were randomly assigned to experimental (EG, n = 45) and control (CG, n = 45) groups. A wide range of sociodemographic, cognitive, psychosocial, and functional conditions were evaluated before, at the conclusion, and 24 months after CI. Data about lifestyle and drug prescription were also recorded.

Results

Baseline evaluations revealed that higher cortisol levels correlated with worse cognitive status (higher CDR and ADAS-Cog values and lower MMSE scores), increased depressive symptoms, and reduced physical and social engagement. Following CI, EG exhibited reduced cortisol levels, improved overall cognitive status, and enhanced verbal working memory and executive functions compared to CG. However, at the 24-month follow-up, EG displayed a rebound effect, characterized by elevated cortisol levels and cognitive decline compared to CG.

Conclusions

These findings strengthen the adverse relationship between excessive cortisol and deficits in cognition/behavior in AD, demonstrate the short-term benefits of CI, and emphasize the potential long-term risks, which may be attributed to the fragile nature of the AD brain. Comprehensive interventions can yield positive results, but careful calibration of type and duration is necessary, considering disease progression and the potential need for re-administration.

Repeated lipoprotein apheresis and immune response: Effects on different immune cell populations

BACKGROUND

Atherosclerosis is considered a chronic inflammation of arterial vessels with the involvement of several immune cells causing severe cardiovascular diseases. Lipoprotein apheresis (LA) improves cardiovascular conditions of patients with severely disturbed lipid metabolism. In this context, little is known about the impact of LA on various immune cell populations, especially over time.

METHODS

Immune cells of 18 LA-naïve patients starting weekly LA treatment were analyzed before and after four apheresis cycles over the course of 24 weeks by flow cytometry.

RESULTS AND CONCLUSIONS

An acute lowering effect of LA on T cell and natural killer (NK) cell subpopulations expressing CD69 was observed. The non-classical and intermediate monocyte subsets as well as HLA-DR⁺ 6-sulfo LacNAc⁺ monocytes were significantly reduced during the apheresis procedure. We conclude that LA has the capacity to alter various immune cell subsets. However, LA has mainly short-term effects than long-term consequences on proportions of immune cells.

Changes in Water Properties in Human Tissue after Double Filtration Plasmapheresis-A Case Study

Double-filtration plasmapheresis (DFPP) is a blood cleaning technique that enables the removal of unwanted substances from the blood. In our case study, we performed near-infrared (NIR) spectroscopy measurements on the human hand tissue before and after a specific DFPP treatment (INUSpheresis with a TKM58 filter), along with NIR measurements of the substances extracted via DFPP (eluate). The spectral data were analyzed using the aquaphotomics approach. The analysis showed that the water properties in the tissue change after DFPP treatment, i.e., an increase in small water clusters, free water molecules and a decrease in hydroxylated water as well as superoxide in hydration shells was noted. The opposite effect was observed in the eluates of both DFPP treatments. Our study is the first that documents changes in water spectral properties after DFPP treatments in human tissue. The changes in tissue water demonstrated by our case study suggest that the positive physiological effects of DFPP in general, and of INUSpheresis with the TKM58 filter in particular, may be associated with improvements in water quality in blood and tissues.

Danggui-Shaoyao-San Attenuates Cognitive Impairment via the Microbiota-Gut-Brain Axis With Regulation of Lipid Metabolism in Scopolamine-Induced Amnesia

Danggui-Shaoyao-San (DSS) has a long history of being used as a traditional medicine (TCM) and has been reported to show therapeutic effects in alleviating the symptoms of cognitive impairment. The purpose of this study was to investigate whether DSS treatment attenuates cognitive impairment via the microbiota–gut–brain axis in scopolamine-induced amnesia. In this work, we first performed the Morris water maze (MWM) test and novel object recognition (NOR) test to evaluate the memory function of treated C57BL/6N mice. Then we evaluated 16S rRNA for gut microbiota analysis, as well as assessment of blood–brain barrier function and intestinal barrier function and lipid metabolism analysis on tissues from different groups. We hypothesised that DSS may affect brain function and behavior through the gut–brain axis in a bidirectional interplay with both top-down and bottom-up regulation. Furthermore, in order to confirm whether intestinal flora plays a crucial role in scopolamine-induced amnesia, C57BL/6N mice were treated with fecal microbial transplantation (FMT), and then behavioral tests were performed. The mice’s feces were simultaneously evaluated by 16S rRNA analysis. The result supported that the FMT-induced improvement in cognitive function highlights the role of the gut microbiota–brain axis to mediate cognitive function and behavior. Besides theses works, more findings indicated that DSS altered lipid metabolism by activating LXR-PPAR-γ and repaired mucosal barrier dysfunction assessed with a broad range of techniques, which attenuated cognitive impairment via the microbiota–gut–brain axis.

The Application of Modified SBA-15 as a Chemosensor

:

The Santa Barbara Amorphous (SBA-15), with a large surface area covered with abundant Si-OH active groups on the walls of its pores, can be modified with various organic compounds to build organic-inorganic hybrid materials, which can be used as a catalyst in organic reactions, drug delivery systems, nano sorbent due to its high capacity for removing heavy metals in waste water and as chemosensors for ions. Tunable and straight channels of SBA-15 facilitate the entrance and diffusion of ions through the channels. This paper presents a review of the past five years of literature covering the application of SBA-15 as an ions chemosensor in the liquid and gaseous media.

Chronic post-COVID-19 syndrome and chronic fatigue syndrome: Is there a role for extracorporeal apheresis?

As millions of patients have been infected by SARS-CoV-2 virus a vast number of individuals complain about continuing breathlessness and fatigue even months after the onset of the disease. This overwhelming phenomenon has not been well defined and has been called "post-COVID syndrome" or "long-COVID" [1]. There are striking similarities to myalgic encephalomyelitis also called chronic fatigue syndrome linked to a viral and autoimmune pathogenesis. In both disorders neurotransmitter receptor antibodies against ß-adrenergic and muscarinic receptors may play a key role. We found similar elevation of these autoantibodies in both patient groups. Extracorporeal apheresis using a special filter seems to be effective in reducing these antibodies in a significant way clearly improving the debilitating symptoms of patients with chronic fatigue syndrome. Therefore, such a form of neuropheresis may provide a promising therapeutic option for patients with post-COVID-19 syndrome. This method will also be effective when other hitherto unknown antibodies and inflammatory mediators are involved.

Alterations of Plasma Lipids in Adult Women With Major Depressive Disorder and Bipolar Depression

Lipidomics has been established as a potential tool for the investigation of mental diseases. However, the composition analysis and the comparison of the peripheral lipids regarding adult women with major depressive depression (MDD) or bipolar depression (BPD) has been poorly addressed. In the present study, age-matched female individuals with MDD (n = 28), BPD (n = 22) and healthy controls (HC, n = 25) were enrolled. Clinical symptoms were assessed and the plasma samples were analyzed by comprehensive lipid profiling based on liquid chromatography-mass spectrometry (LC/MS). We found that the composition of lipids was remarkably changed in the patients with MDD and BPD when compared to HC or compared to each other. Moreover, we identified diagnostic potential biomarkers comprising 20 lipids that can distinguish MDD from HC (area under the curve, AUC = 0.897) and 8 lipids that can distinguish BPD from HC (AUC = 0.784), as well as 13 lipids were identified to distinguish MDD from BPD with moderate reliability (AUC = 0.860). This study provides further understanding of abnormal lipid metabolism in adult women with MDD and BPD and may develop lipid classifiers able to effectively discriminate MDD from BPD and HC.

High fat diet-induced obesity leads to depressive and anxiety-like behaviors in mice via AMPK/mTOR-mediated autophagy

Depression is one of the most common mental illnesses in modern society. In recent years, several studies show that there are disturbances in lipid metabolism in depressed patients. High-fat diet may lead to anxiety and depression, but the mechanisms involved remain unclear. In our study, we found that 8 weeks of high-fat feeding effectively induced metabolic disorders, including obesity and hyperlipidemia in mice. Interestingly, the mice also showed depressive and anxiety-like behaviors. We further found activated microglia and astrocyte, increased neuroinflammation, decreased autophagy and BDNF levels in mice after high-fat feeding. Besides, high-fat feeding can also inhibit AMPK phosphorylation and induce mTOR phosphorylation. After treating with the mTOR inhibitor rapamycin, autophagy and BDNF levels were elevated. The number of activated microglia and astrocyte, and pro-inflammation levels were reduced. Besides, rapamycin can also reduce the body weight and serum lipid level in high fat feeding mice. Depressive and anxiety-like behaviors were also ameliorated to some extent after rapamycin treatment. In summary, these results suggest that high-fat diet-induced obesity may lead to depressive and anxiety-like behaviors in mice by inhibiting AMPK phosphorylation and promoting mTOR shift to phosphorylation to inhibit autophagy. Therefore, improving lipid metabolism or enhancing autophagy through the AMPK/mTOR pathway could be potential targets for the treatment of obesity depression.

Liposome-based targeting of dopamine to the brain: a novel approach for the treatment of Parkinson's disease

Delivery of drugs into the brain is poor due to the blood brain barrier (BBB). This study describes the development of a novel liposome-based brain-targeting drug delivery system. The liposomes incorporate a diacylglycerol moiety coupled through a linker to a peptide of 5 amino acids selected from amyloid precursor protein (APP), which is recognized by specific transporter(s)/receptor(s) in the BBB. This liposomal system enables the delivery of drugs across the BBB into the brain. The brain-directed liposomal system was used in a mouse model of Parkinson's disease (PD). Intra-peritoneal (IP) administration of liposomes loaded with dopamine (DA) demonstrated a good correlation between liposomal DA dose and the behavioral effects in hemiparkinsonian amphetamine-treated mice, with an optimal DA dose of 60 µg/kg. This is significantly lower dose than commonly used doses of the DA precursor levodopa (in the mg/kg range). IP injection of the APP-targeted liposomes loaded with a DA dose of 800 µg/kg, resulted in a significant increase in striatal DA within 5 min (6.9-fold, p < 0.05), in amphetamine-treated mice. The increase in striatal DA content persisted for at least 3 h after administration, which indicates a slow DA release from the delivery system. No elevation in DA content was detected in the heart or the liver. Similar increases in striatal DA were observed also in rats and mini-pigs. The liposomal delivery system enables penetration of compounds through the BBB and may be a candidate for the treatment of PD and other brain diseases.

Effects of safflower yellow on cholesterol levels in serum and brain tissue of APP/PS1 mice

Alzheimer's disease (AD) is an aggressive neurodegenerative disease associated with cognitive decline, memory, language, and visual-spatial coordination disorders that eventually lead to complete loss of basic function. Hypercholesterolemia plays an important role in the pathogenesis of AD and its related diseases. Safflower yellow (SY) is a natural chalcone compound isolated from safflower, which has the effect of antioxidation and weight loss. Previous studies have shown that SY has a significant improvement in learning and memory in various AD model animals. In the early stage of proteomic technology, we found that the cholesterol synthesis rate-limiting enzyme Mevalonate decarboxylase (MVD) was abnormally high in dementia rats, and the expression level of MVD decreased after SY treatment. We speculated that SY may improve the learning and memory ability of AD mice by affecting cholesterol metabolism. The purpose of this study was to evaluate the effect of SY on regulating cholesterol metabolism and improving dementia. The area of amyloid-β (Aβ) plaque in the brain of APP/PS1 mice and various blood biochemical and molecular biological indexes was detected. Through behavioral experiments, we found that APP/ PS1 mice had significant learning and memory impairment compared with wild type mice(P < 0.01). SY (30 mg/kg) treatment for 1 month can significantly improve the learning and memory ability of APP/PS1 mice (P < 0.01). Our results showed that SY decreased serum Total cholesterol (TC) and Triglyceride (TG) and increased the level of High-density lipoprotein (HDL). HE staining obscured that SY affect the changes of liver tissue in APP/PS1 mice (P < 0.05 and P < 0.01). We found that SY reduced the expression of MVD and Apolipoprotein E (APOE4) in the cortex (P < 0.05 and P < 0.01). In summary, SY can effectively control cholesterol in serum and brain and change the degeneration of liver tissue. SY improves Alzheimer's disease by lowering serum, cortex and cortical cholesterol.

The chronic effect of cortisol on orchestrating cerebral blood flow and brain functional connectivity: evidence from Cushing's disease

BACKGROUND

Cortisol has long been considered to play a crucial role in the pathogenesis of stress-related disorders. Cushing's disease (CD) provides an excellent "hyperexpression model" to investigate the chronic effects of cortisol on brain physiology and cognition. Previous studies have shown that cortisol is associated with neurophysiological alterations in animal models, which has also been examined by neural activity and cerebral blood flow (CBF) in human studies. However, the manner in which cortisol affects the coupling between brain activity and metabolic demand remains largely unknown.

METHODS

Here we used functional magnetic resonance imaging and arterial-spin-labeling imaging to investigate neurophysiological coupling by examining the ratio of CBF and functional connectivity strength (FCS) in 100 participants (47 CD patients and 53 healthy controls).

RESULTS

The results showed that CD was associated with lower CBF-FCS coupling predominantly in regions involving cognitive processing, such as the left dorsolateral prefrontal cortex and precuneus, as well as greater CBF-FCS coupling in subcortical structures, including the bilateral thalamus, right putamen, and hippocampus (P < 0.05, false discovery rate corrected). Moreover, regions with disrupted CBF-FCS coupling were associated with cortisol dosage and cognitive decline in CD patients.

CONCLUSIONS

Together, these findings elucidate the effect of cortisol excess on cerebral microenvironment regulation and associated cognitive disturbances in the human brain.

A glimpse at growth hormone-releasing hormone cosmos

Growth hormone-releasing hormone is a hypothalamic neuropeptide, which regulates the secretion of growth hormone by the anterior pituitary gland. Recent evidence suggest that it exerts growth factor activities in a diverse variety of in vivo and in vitro experimental malignancies, which are counteracted by growth hormone-releasing hormone antagonists. Those peptides support lung endothelial barrier integrity by suppressing major inflammatory pathways and by inducing the endothelial defender P53. The present effort provides information regarding the effects of growth hormone-releasing hormone in the regulation of P53 and the unfolded protein response. Furthermore, it suggests the possible application of growth hormone-releasing hormone antagonists towards the management of acute lung injury, including the lethal acute respiratory distress syndrome.